Working with your own sister? Some celebrities think it’s the key to success and have created their very own fashion lines, keeping it all in the family. Famous sisters Sienna and Savannah Miller, Mary-Kate and Ashley Olsen, and Penelope and Monica Cruz have jumped in on this trend, reaping the benefits of having a reliable business partner.

British icon Sienna Miller has been known for her outfits as well as her acting skills. What most don’t know is that she has a designer for her sister. Savannah, three years older than Sienna, studied fashion design in Central Saint Martin’s in London and under such designers as Alexander McQueen and Betty Jackson. During a brief time when the sisters lived together, Sienna would serve as Savannah’s muse, inspiring her with her quirky attitude, comments, and even standing in as a fit-model.

“Sienna’s always been quite forward-thinking in her approach to fashion, so working with her is great as she comes up with crazy ideas that I perhaps wouldn’t otherwise consider,” Savannah said about her sister on the fashion line’s Web site (twenty8twelve.com). “She’s also great to bounce ideas off and was an excellent fit-model when I was freelancing.”

Sienna feels the same closeness to her sister. “Sav is the closest person to me,” she said in a recent article featured in Vogue Spain. “Now I’m working with her…what could be more fun?”

Their fashion line, Twenty8Twelve, is named after Sienna’s birthday. Sienna serves as the creative thinker, while Savannah stands in as the detail-oriented designer.

“I tell Savannah what I like, and she, who’s used to designing, is the one in charge of the details,” Sienna said in a recent interview with Glamour Spain. “I don’t pretend to make myself draw. I’m not an expert on the technical side of fashion, but I let my instincts take over.”

Their 80-piece line debuted in September in Nieman Marcus and Bergdorf Goodman. The line has vintage feminine touches with an air of masculinity. Their style is set to target the mid-range when it comes to high-fashion versus cheap clothing.

“It’s designed to cover the gap that exists between very cheap clothing but that’s not of good quality, and that of great designers, that is exceptionally expensive and that you don’t even think of buying when your 28,” Savannah told Glamour.

Twin actors Mary-Kate and Ashley Olsen are also forward thinking fashionistas who have graduated from kid-friendly outfits to an edgier adult line. Known for their commercial appeal, the sisters already have been the face of their own clothing line, which was sold at Wal-Mart, when they were young. The difference was that the clothing was targeted at young girls and the twins had no say or input in the designing process. That all has changed with the introduction of their first high-fashion line, The Row.

“We want to control its image and each piece and each collection,” Mary-Kate said about the new line to Women’s Wear Daily. “The Row is very separate from everything we’ve done so far.”

Ashley added, “It’s definitely in a different marketplace.”

The line falls under a palette of dark hues, ranging from charcoal gray to pitch black, with just hints here and there of the purest white. In the U.S., the line is sold at Barney’s New York and Maxfield in Los Angeles. It includes such pieces as “$3,220 Tuscan lamb-fur coats, $1,700 cashmere tuxedo jackets with three-quarter sleeves, $875 banded strapless dresses and $360 legging-style pants,” according to the article in Women’s Wear Daily.

The twins’ newest line, Elizabeth and James, which is named after two of their siblings, shows a wider range of patterns and hues. “The spring collection, which will be the second season for Elizabeth and James, includes silk chiffon printed tops, high-waisted pants, slim skirts, leather jackets, evening gowns and silk party dresses,” according to another recent article in Women’s Wear Daily. The line is mainly sold on the West Coast by Neiman Marcus but is expanding to include wider spread audience. Elizabeth
and James seems to be the brighter, more upbeat counter part of the older Row pieces.

“When I hear ‘The Olsen Twins,’ I think original, offbeat, and eye-catching,” said Avellana. “This is why I was disappointed when I saw their lines. You’d think a pair of fashionistas like the Olsen twins would pull off a great line, but they ended up coming out with the stuff H&M put on clearance in March.”

Spain’s leading actresses Penelope and Monica Cruz have also created their own Spanish-inspired line for Spain’s worldwide chain Mango. Modeling in the line’s ads, the sisters have designed a 25-piece collection (with prices ranging from $29 to 219) that includes exotically printed tops, oversized pants, retro and balloon minidresses, winter coats, and accessories, according to the chain’s Web site, mango.com. The Cruz sisters have been inspired by simple things, such as paintings and books on photography, and the very 50’s and 60’s eras to create this distinct, yet oh-so-Cruz style.

“[The line] is thinking about all women, [it’s] following trends, but it’s comfortable and elegant,” Monica said in a recent article in Glamour Spain.

FDU freshman Karina Rodriguez picks the Cruz sisters’ line for Mango as her favorite among the lines mentioned.

“Their clothes are edgy, yet still have a sophisticated tone to them,” she said.

What stands out as distinct from other contemporary lines is that the Cruzes’ exotic jacket pieces are made with only fake fur.

Having some experience in designing for Japanese brand Samantha Thavasa, along with being part of the glamorous world of the movies, fashion is not new to the Cruz sisters.

“Designing for Samantha Thavasa has given us some experience,” Penelope told Glamour. “But we have to be humble; it’s the first time that we make clothing. We love this world, we are really in touch with it because of our line of work. We dedicate time to it and we know about the topic, even though we aren’t professional designers.”

Students tend to think that a sister relationship, like that of the Millers, the Olsens, and the Cruzes, would be successful.

“I believe there could be a lot of success between sibling business partners,” said Rodriguez. “Not only do they understand each other better than say friends would, but they are also more likely to try and work out any problems that may arise in the process of creating a fashion line.”

Yet other students do believe that some tensions may arise out of a sister-sister business relationship.

“On one hand, they could be very successful because their lines could complement each other and they would obviously get along if they were business partners,” Junior Puja Patel said. “But then again…when people who know each other go into business together, their relationships tend to become strained.”

The Cruz sisters have proven otherwise, showing that working with one’s sibling is not only rewarding, but much easier in terms of communication.

“When we get together, we realize that the two of us are following the same path,” Penelope told Glamour. “We have a lot of telepathy,it’s something very curious…We’re a great team.”